岩溶地区典型铅锌尾砂重金属赋存特性及生态风险  

Occurrence characteristics and ecological risk assessment of heavy metals in tailing in karst lead-zinc tailing ponds in Guizhou Province

作　　者：刘博 肖涵 韩志伟[1,2] 欧阳及第 白子尤 李沁缘 LIU Bo;XIAO Han;HAN Zhiwei;OUYANG Jidi;BAI Ziyou;LI Qinyuan(Resource and Environmental Engineering College,Guizhou University,Guiyang,550025,China;Key Laboratory of Karst Georesources and Environment,Ministry of Education,Guiyang,550025,China)

机构地区：[1]贵州大学资源与环境工程学院,贵阳550025 [2]贵州大学喀斯特地质资源与环境教育部重点实验室,贵阳550025

出　　处：《环境化学》2024年第9期3080-3091,共12页Environmental Chemistry

基　　金：国家重点研发计划项目(2018YFC1801705);贵州省人才基地工程(RCJD2018-21)资助.

摘　　要：岩溶发育导致喀斯特生态环境具有脆弱性,矿业开发造成尾砂大量堆存,当前尾砂重金属对岩溶生态系统的影响尚不清晰.为探讨岩溶地区铅锌矿尾砂重金属分布特征及潜在生态风险.以黔南牛角塘1—10号铅锌尾矿库作为研究区域采集尾砂样品,对重金属总量和赋存形态进行分析;利用内梅罗污染指数(NPI)、潜在生态风险指数(RI)、风险评估指数(RAC)、次生相原生相分布比值法(RSP)评价尾砂重金属环境效应,揭示铅锌矿尾砂重金属的污染风险.结果表明,Cd在1—10号全部点位、Zn在70%点位、Cr在50%点位处存在显著高值,Cd、Zn和Cr含量均值为58.09、4640、2747 mg·kg^(-1),分别是贵州省土壤背景值的88.15、46.63、28.64倍;Cd和Zn有效态含量分别占4种形态总和的50.75%、44.20%,Cr主要以残渣态为主,在尾砂中性质较稳定;NPI与RI评价显示,Cd、Zn、Cr、Cu在1—10号全部点位处呈现严重生态污染风险;RAC与RSP评估显示,Cd与Zn在50%点位处呈现极高风险的环境污染,存在Zn和Cd单项和复合污染情况,Cd的活动性与生物可利用性更强,尾砂重金属所产生的环境生态风险主要来源于Cd的高含量.本研究为岩溶地区同类型尾矿区重金属污染分析、风险评价及防治提供了基础数据支撑.Karst development leads to the fragility of karst ecological environment,and mining development leads to the accumulation of tailings in large quantities.At present,the impact of heavy metals in tailings on karst ecosystem is still unclear.In order to explore the distribution characteristics and potential ecological risks of heavy metals in lead—zinc tailings in karst area.Taking Niujiaotang 1—10 Lead—zinc tailings pond in southern Guizhou as the study area,tailings samples were collected to analyze the total amount and occurrence forms of heavy metals.Nemerow pollution index(NPI),potential ecological risk index(RI),risk assessment index(RAC),secondary primary phase distribution ratio method(RSP)were used to evaluate the environmental effects of heavy metals in tailings,and to reveal the pollution risk of heavy metals in lead—zinc mine tailings.The results showed that Cd,Zn and Cr had significant high values at all 1—10 sites,70%and 50%sites,and the average contents of Cd,Zn and Cr were 58.09,4640 and 2747 mg·kg^(-1),88.15,46.63 and 28.64 times of the background values in Guizhou Province,respectively.The available state content of Cd and Zn accounted for 50.75%and 44.20%of the total of the four forms,respectively.Cr was mainly in the residual state,which was stable in tailings.NPI and RI evaluation showed that Cd,Zn,Cr and Cu presented serious ecological pollution risk at all sites from 1 to 10.RAC and RSP evaluation showed that Cd and Zn presented extremely high risk environmental pollution at the 50%point,and there were single and combined pollution of Zn and Cd.Cd activity and bioavailability were stronger,and the environmental ecological risk caused by heavy metals in tailings mainly came from the high content of Cd.This study provides basic data support for the analysis,risk assessment and prevention of heavy metal pollution in similar tailing mining areas in karst areas.

关 键 词：铅锌矿 重金属 赋存特征 风险评价 喀斯特 

分 类 号：X-1[环境科学与工程] O6[理学—化学]